Firewall (computing) - Wikipedia
https://en.wikipedia.org/wiki/Firewall_(computing)
In computing, a firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.[1] A firewall typically establishes a barrier...
10 Best Free Firewall Programs (Updated March 2021)
https://www.lifewire.com/free-firewall-programs-4129270
Windows does have a firewall built-in, but did you know there are other options? Here's a list of the best free firewall programs we could find. A list of the best free firewall programs for Windows.
Безопасность - Firewalls
https://www.SoftPortal.com/dlcategory-222-1-0-0-0.html
Windows Firewall Notifier 2.0 beta 3. RusRoute firewall 2.1.3.
What Is a Firewall? - Cisco
https://www.cisco.com/c/en/us/products/security/firewalls/what-is-a-firewall.html
A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules.